


Just Between Us

by AphAfterDark



Category: Voltron: Legendary Defender
Genre: Age Difference, Alien Biology Keith, Creampie, DubCon to NonCon, Galra Puberty, Grooming, Hand Jobs, M/M, Male Lactation, Oral Sex, Penis In Vagina Sex, Sex addiction caused by hormones, Sibling Incest, Squirting, Underage Sex, Virgin!Keith, Wet & Messy, afab language
Language: English
Status: Completed
Published: 2020-07-12
Updated: 2020-07-12
Packaged: 2021-03-04 19:41:43
Rating: Explicit
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 10,150
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25221826
Author URL: https://archiveofourown.org/users/AphAfterDark/pseuds/AphAfterDark
Summary: Keith shifts against his brother's thigh, and the fabric of his boxers chafes. It sends spindles of sensation through him, and he can’t help the gasp. It’s overwhelming, like it was in his own bed, but less scary now. Shiro’s still holding him, so everything’s okay.The next time he moves his hips, it’s purposeful. He rubs that little bundle of nerves against Shiro, biting his lip at how it rattles through him. His body drives him forward, drives him for more.
Relationships: Keith/Shiro (Voltron)
Comments: 24
Kudos: 493





	Just Between Us

**Author's Note:**

> **Content warnings: READ THE TAGS. Herein Keith is going through Galra puberty, he is underage but no specific age is listed. Shiro and Keith are half-brothers. Keith is male but with a vagina per his Galra heritage, AFAB language is used extensively. Dub/noncon tag for Keith being underage, being influenced by his hormones, and being groomed/pressed in sexual situations, it is done rather softly by Shiro, Shiro genuinely cares about him herein, but I'm tagging for extra safety.**   
>  **If you've read my other redacted, it's the same sort of vibe, some dark kinky times, but not mean.**
> 
> Fic requested by @pissangel!

It’s a nagging something in the back of Keith’s head at first. An almost nothing. He ignores it, busy with classes, aiming for the best grades, the top sim scores. His older half-brother Shiro is just finishing up his classes at the Garrison, looking to move in Garrison staff next year, and Keith’s only goal is to get in.

Shiro’s assured him more than once that he’s a sure thing, but Keith doesn’t want to rely on his connection to Shiro, he wants to be good enough.

So if he starts waking up over hot and sweaty and feeling a strange kind of buzzing under his skin, he ignores it. He figures it’s puberty, and there’s no time to spend thinking about it because he has a goal, a future.

Shiro promised him that if he got into the Garrison someday they could fly together, and Keith aims to make that a reality. He wants little else.

Still, by the time summer arrives, Keith is hard up to ignore his body’s changes. He’s horny _all the time_ now, and it’s getting difficult to do anything. It’s been years since the sex talk, and since the other guys in his class started talking almost exclusively about sex and how to have it, but for some reason Keith had always assumed he was above that. It had skipped him then, whatever was driving the other kids in his class. Now he sees he was just a little late.

He wakes, a week into summer break, flushed and a mess. There’s wetness between his thighs and a throbbing in his body. He groans and rolls over, trying to ignore it. The shift only serves to put pressure on his clit, and he has to squeeze his legs together at how it pulses through him.

He’s touched himself before, a few times. Felt down between his legs when the wetness had started, touching the soft heat there. It had felt strange, kind of embarrassing, and he hadn’t gone further. He knows there’s things people do with this kind of feeling, but he doesn’t know if he should.

It’s scary, almost. Too new. Too… weird.

He knows he’s different from a lot of other people too in this area. His father had that conversation with him years upon years ago, about why Keith didn’t go to most doctors, and why he should avoid letting people see him naked. It hadn’t been a shame thing, in fact at the time it had made Keith proud.

 _You’re like your mother_ , his father had said, _and she was very different. Very different and very amazing_.

But now, with his body feeling so strange and this urge inside him taking up so much space, Keith doesn’t think he likes whatever this _different_ thing is.

He sits up then in a huff. Every other time that Keith’s been confused or frustrated about something, he’s taken it to Shiro. He doesn’t see why this should be any different. Maybe he could even help with this… whatever it is. Give Keith tips maybe.

Anything is better than either trying to ask their dad, or suffering alone.

Keith gets up and goes to his door. It’s early, too early, and the house is completely silent. Their dad won’t be up until much later due to his last overnight shift. Keith tiptoes quietly across the hall, and then eases Shiro’s bedroom door open.

His brother is sprawled in the bed, not snoring but breathing deep and rhythmic. He looks cozy, rumbled. Keith pads over and carefully lifts the covers on the side with more room, and eases himself down onto the bed.

Shiro shuffles a little with the motion, making a sleepy noise but moving his flung limbs out of Keith’s way. It’s far from the first time Keith’s snuck into Shiro’s bed for a late-night or early morning confidence between them.

Shiro turns onto his side as Keith settles down completely. It’s a clear signal, and Keith moves closer until his big brother wraps an arm around his middle and draws him in. It’s snug and a little too warm, but Keith sighs happily into it.

“Ok?” Comes Shiro’s sleep-roughened voice.

Keith hums. He wants to talk, but surely it can wait. He wants Shiro to be rested, and here and now he doesn’t want to disturb this nice cocoon he’s gotten himself into. Shiro is so big and solid compared to Keith. Keith has yet to broaden and get the height his father promised he would get from his mother. He has no doubts it’ll come with time, so for now he doesn’t mind being so slight. He fits right up against Shiro so perfectly.

It’s easy then to doze. It’s dark and quiet and Shiro’s steady breathing lulls him in. It’s not full sleep, he can still feel the itch of his body, but it’s helped by the strong arm wrapped around him. His mind drifts as it does too often to Shiro. So good and kind, the best brother Keith could ask for. There’s little space left between them but Keith pushes closer still, nuzzling into Shiro’s chest.

The man shifts his leg in response, and Keith takes the opportunity to entwine them. It allows him to press right up against Shiro’s thigh and—

 _Oh_.

There’s a throb of pleasure at how Keith’s crotch comes in contact with the hardness of Shiro’s thigh. He feels between his legs clench. It feels good. So good.

He shifts against Shiro’s thigh, and the fabric of his boxers chafes. It sends spindles of sensation through him, and he can’t help the gasp. It’s overwhelming, like it was in his own bed, but less scary now. Shiro’s still holding him, so everything’s okay.

The next time he moves his hips, it’s purposeful. He rubs that little bundle of nerves against Shiro, biting his lip at how it rattles through him. His body drives him forward, drives him for more.

He does so in little movements, rubbing himself against Shiro. It doesn’t take much, his body is already doing something that Keith doesn’t have words for. It’s thrilling, to be doing this here, doing this scary thing in such a safe place. There’s something his body is moving toward, he can feel it as his hips fall into a rhythm. He—

“Ke?” Comes a whisper from Shiro.

Maybe the proper thing would be to stop, to freeze up or flee in embarrassment, but that’s just not the relationship they have. Shiro knows everything about him, the good and the bad. There’s nothing that they haven’t shared.

Except maybe…

So he doesn’t stop moving. He pushes against Shiro’s thigh, nuzzling his brother’s chest.

“Shiro— I— it feels—“ the words don’t come.

Shiro pulls back then. Not much, not enough to really put space between them, but enough to see Keith’s face.

“Keith? You’re…”

“It just started,” Keith blurts. “And I don’t know. I just. It _aches_.”

“Oh,” Shiro says. His hand moves up soothingly over Keith’s back and then cards through his hair. “Aches down there?”

“Yeah.”

His hand scratches across the back of Keith’s nape, and there’s a whole body shiver that comes with it.

“And that feels good?”

There’s a hot flush across Keith’s cheeks. He tilts his head back down into Shiro’s chest and nods. A moment later Shiro’s finger is below his chin, tipping his head up once more.

“What do you need Keith?”

“I— I don’t know. Help?” His head feels like a mess of things, and none of them are words he could give to Shiro.

Shiro, wonderful Shiro, seems to get it anyway.

“Okay,” he says. “I’ll help.”

Then that large hand is sliding back down Keith’s body, but instead of his waist, it wraps around Keith’s hip. There’s a firm grip, and then Shiro is taking control of the motion, moving Keith’s hips. His leg is still between Keith’s, and it shifts up and presses more firmly against Keith’s clit.

All at once there’s a sharp spike of sensation. Keith cries out on a breath. Quickly, Shiro’s other hand covers his mouth.

“Shh. You have to be quiet, okay? I can take care of you, but you’ve gotta be quiet for me.”

“Sorry,” Keith whispers when the hand lifts off. “It was just, a lot.”

Shiro’s beginning to guide his body faster, and any further words just disintegrate in Keith’s mouth.

“Good a lot or bad a lot?”

Keith buries his face against Shiro to stifle the sounds that he wants to make. There’s something building inside him, much heavier than anything that came before. His hands curl into Shiro’s sleep shirt, and he hopes by the way he plasters himself close it’s an answer.

Shiro hums. “Okay, good then. Just…”

It’s long hard grinds that Shiro starts him on. Keith’s body is out of his control, burning and flooding, but for once he gives himself over to it. Shiro’s in control and won’t let anything bad happen to him. If anything, the way his insides are squirming, there’s a very good something coming

He does his best to quiet his own sounds, but it’s hard, so hard. Everything feels like a whirlwind, there’s only Shiro that’s stable. He clings, feeling the pleasure crest higher and higher inside him, like nothing has ever been.

“That’s it, perfect Keith,” Shiro croons. His voice is low and deep. It’s different than his normal voice, but it prickles down Keith’s spine. “Just focus on how it feels, let yourself slip into it.”

Shiro’s breathing hard, his hand clutched almost painfully on Keith’s hip, but Keith likes it, he likes all of it. He ruts against Shiro’s thigh, his boxers drenched, clit throbbing and—

And then something in him _breaks_.

He doesn’t know any better way to put it. Once moment he’s soaring, above the clouds and breathless, mewling against Shiro’s skin, and then it’s like a wall, or a ledge rises before him and he tumbles right into it. His whole body shakes, pulse after pulse, and he cries out before Shiro tugs him in and presses his face to Shiro’s shirt. He keeps Keith moving, riding out the pleasure as his pussy clenches, wetness flooding out of him.

It’s like everything in the whole world collapses into itself in a whiteness that feels—

 _Unexplainable_.

There just aren’t words.

The pulses slow, gentling him back down and he gasps for air. Shiro slows and then stops just as Keith’s body slides into over-stimulation. Gently Shiro pushes Keith back into the sheets and pulls away the covers to give them both some air.

It feels incredible. Everything feels incredible. Keith opens his eyes to the darkened bedroom and can’t help the smile on his face. When he turns his head Shiro is watching him.

“Was that… okay?”

“Yeah,” Keith’s throat is a little dry, but he doesn’t even care. “I feel like I’m floating. Is that… is it like that all the time?”

There’s a sharp intake of breath from Shiro. The eyes on him are intent, and there’s a strange look Keith’s never seen before, but he likes it. He likes it focused on him. “Have you never… was that your first orgasm?”

Keith’s eyes flicker away. He feels suddenly shy. He knows most of the other kids have already done it, and that he’s rather late to the game.

“Yeah.”

There’s a low curse from Shiro. It’s almost the most shocking part of what just occurred, Shiro never, ever curses.

“No, not you. I mean. That’s fine. Just fine that was your first time. I just didn’t know,” Shiro says quickly.

“Is that okay?”

Shiro leans in then, curling hands back around Keith and pulling him into a hug. “Of course, of course Keith. That was… it was an honor, to be trusted. To be able to give you that.”

“It was… good. Felt good with you. Not as scary as I thought.”

Shiro makes a sound, and it’s then that Keith notices a… hardness against him.

“That’s good. Want you to feel good.”

“Shiro… do you want to, uh.”

“Oh.” Shiro pulls back then, or tries to but Keith’s hands latch on.

“Don’t go!”

His voice comes out a little too shrill, a little too wavering. Immediately Shiro is back in his space, petting his shoulder.

“Okay, shh. It’s okay.”

“Sorry,” Keith says, feeling a little foolish for the outburst.

“It’s okay. But uh, I have to go take care of this.”

Keith’s hands tighten in Shiro’s shirt. “I can help,” he blurts at once. “Uh. If you want.”

Shiro’s hands slide down Keith’s trim body, as though taking the measure of him “Help?”

“Yeah. You helped me.”

“Oh Keith…” The hands slide down to cup Keith’s ass. It’s a firm grasp, possessive almost. “I wouldn’t want you to be uncomfortable. This was about you, it doesn’t _have_ to be reciprocal.”

As he says it though, his erection bumps Keith’s leg. It’s big.

“O-oh.” The thought and the reality come together then for Keith and it’s kind of intimidating. He’s never even thought of something like this before now. It feels so much so suddenly.

There’s a beat then where nothing happens. Then Shiro says, “But you don’t want me to go?”

Keith shakes his head. He swallows hard and tries to rally his courage. “No. Just… I can help.”

Shiro presses closer, his cock sliding against Keith’s thigh. The sleep shorts are still preserving his modesty, but the action makes a shiver run through Keith. “You sure?”

Keith can’t get any more words out, but he nods.

The next thing he knows a hand is moving off his waist, and then Shiro is tugging his own shorts down. His cock bounces up, slapping gentle against Shiro’s stomach.

It’s a momentary shock to see one in real life. Keith’s seen porn and plenty of media, but this is his first actual experience.

“It’s so big,” Keith says. Because it is. Right there next to Keith’s thigh, Shiro’s cock is huge. It’s hard and heavy and reddened at the tip.

“Mhm.” Shiro wraps a hand around his cock and then gives it one long stroke. Keith watches the head be covered and uncovered by the foreskin. “Still want to help?”

It’s hardly a choice, Keith can’t stand the idea of Shiro leaving right now. He swallows hard, face burning in both anticipation and arousal.

“What do I do?”

“Similar to what we did for you,” Shiro reaches up and takes one of Keith’s hands off his shirt. “You rub,” he says. He guides Keith’s hand to the head of his cock. When Keith’s smaller hand folds around it, the tip is surprisingly soft.

“ _Oh_.”

“Like this,” and then Shiro guides him gently, moving his hand down to under the head and then back up. “Yeah, this bit is most sensitive, like your clit.”

It’s still shocking to hear Shiro speak like that, to say those words. Keith’s whole body flares with heat, watching his own hand move slowly on Shiro’s cock. He slides the foreskin up and then back down, the ruddy head appearing once more.

On the next stroke up, wetness appears from the tip. It’s clear and a little thick as it begins to drip down. Shiro breathes heavier, body beginning to move.

“That’s it. Feels good Keith.”

Keith’s heart skips at the words. Shiro’s voice is low, soft. Keith focuses harder on what he’s doing, sliding up and down, milking more wetness from the tip. He’s surprised at how hard and soft Shiro’s cock is, it feels nice in his hand, velvety.

“Mmm, tighten a little when— yeah— fuck—“

There’s more wetness then from the tip, and it coats Keith’s hand when he strokes over it. It makes the motion slick and smooth, but best of all is how Shiro reacts. He jerks up into Keith’s hand with a muffled sound.

“Just… yeah… keep going.” His cock is so red and glistening as it begins to thrust through the coil of Keith’s hand. Keith can’t look away, even as the sight burns all the way through him. It’s different, the way Shiro sounds and moves here, but it’s also somehow the same. It’s still Shiro, just this new side of him. A side he’s trusting Keith with.

He watches Shiro’s cock fuck through his hand, over and over. There’s a wet sound, and the cock seems to thicken a little more. Before Keith knows it, Shiro’s whole body turns rigid, and the cock in Keith’s hand thrusts hard and starts pulsing. Come shoots out, surprising Keith into almost pulling his hand away, but then Shiro’s is wrapping his own around Keith’s and guiding him through it.

Shiro spills between them, come getting all over Keith’s shirt and hand and the sheets. It’s a mess of sticky whiteness that awes Keith to see.

Shiro pants through it to stay quiet as he comes down, and it makes Keith feel tingly all over. He likes the power of it, likes knowing he made Shiro feel good.

He thinks he understands, finally, what the fuss is all about.

They don’t do much talking after that. Shiro smiles and kisses his forehead and then, when Keith’s feeling steady, sends him off to the shower. It’s not the most ideal of endings, Keith would rather his brother be in the shower with him, but he also understands that their dad is still home and some caution is probably good.

So when Shiro nudges him off to the shower, he goes. He goes and stands under the spray and thinks about what just happened. It wasn’t anything he had expected, and some of it had been as frightening as it had been thrilling. He’s glad though, in the end, that it had been with Shiro. He knows Shiro would never hurt him, and had, in fact, made him feel good. 

##

The next morning Keith wakes with the same feeling, so he sneaks once more out of his bed and into Shiro’s. He figures if Shiro was willing to help him the first time, there’s no harm in trying again.

“Mmm, morning,” Is the only thing Shiro says, and curls Keith in, offering up his thigh. Keith ruts against him until he comes again, and then even before he’s done he reaches into Shiro’s boxers. Shiro almost gives no help the second time, letting Keith touch and jerk him off, and it makes Keith feel proud when he manages to get Shiro to come.

It’s a little bit more contained the second time, because Keith recognizes the signs and manages to get most of it in his hands.

Shiro’s eyes are watchful on him for a moment then when they finish. It looks like he’s going to ask Keith something, but then changes his mind and instead reaches over to grab a dirty tee off the floor for Keith to wipe his hands off. Keith almost asks what it is, but the come is almost dripping off his hands, so he just takes the shirt.

It goes on like that all week. Keith gets better at using his hands he thinks, or at least he manages to make Shiro come faster. Shiro praises him each time, dropping kisses onto his forehead or cheek. It’s exciting and fun and Keith loves how close it makes him feel to his brother.

It’s surprising then on Saturday morning when Keith climbs into bed and Shiro puts a hand to stop him from curling closer.

“Wait. I have an idea, since Dad’s at work and we don’t have to worry about you being loud.”

Keith flushes in embarrassment. Shiro’s had to muffle him nearly every time he’s come.

“Sorry.”

“It’s okay. I know it’s all new for you Keith. But do you want to try something new?”

Keith nods even if the uncertainty rises in his chest. He reminds himself that this is Shiro. Shiro always takes care of him.

“Okay,” Shiro says, and then reaches for the waistband of Keith’s boxers. He tries not to freeze up when Shiro strips him down. It helps when Shiro’s hands trail back up Keith’s bare thighs with a sound of appreciation.

Then he reaches for his own underwear and pushes them down. Keith’s heartrate spikes. Are they...?

Shiro must see his expression, because he immediately gentles. “No, not that. Just— come here.”

Keith scoots closer on his side, and then has to look down between them. Shiro’s cock is so close to his naked skin.

“Here,” Shiro lifts Keith’s thigh and puts it over his own, “And now,” A large hand wraps around Shiro’s cock and tilts it to touch Keith’s clit. Keith gasps. “See, we could rub both at the same time,” Shiro says, and demonstrates by moving his cockhead against Keith’s clit.

The sensation is softer than rutting against Shiro’s thigh, but the visual of it is…

He squeaks at the next thrust, slickened from how Shiro’s cock has already started to leak.

“How’s that?”

Keith is speechless. The pleasure is already flooding through him, his body so hot from watching Shiro’s cock slide against his little bundle of nerves. It’s the most obscene thing Keith has ever witnessed.

“Good, right?” Shiro grunts, starting to move his hips faster. His eyes are also glued to where they’re rubbing. “Fuck, look at that rosy little clit. You like this don’t you? Like my cock making you feel good?”

Keith can only cry out as Shiro begins to drive in with more force. His hand has move to his cock and is stroking the length, making it bob against Keith’s clit. Bundles of pleasure spark up Keith’s core. Keith feels his pussy begin to ooze at the treatment.

“ _Fuck_ , I’m gonna… yeah… gonna come on that pretty little clit. _Ke_ —“

And then for the first time Shiro is coming first. He’s stroking himself furiously, and coming directly on Keith. He curses loudly as he does so, spilling milky whiteness all over Keith’s clit and abdomen. He fucks through the mess, spreading the wetness as he begins to come down. Keith’s close, so close to his own end just from watching Shiro come, and he whines when Shiro pulls his cock away.

It’s only for a moment though, because then Shiro’s fingers are there. He smears his come around further, keeping up the motion on Keith’s clit. It’s wet and _filthy,_ and Keith can only watch.

“That’s it,” Shiro guides as Keith’s eyes shut and the pleasure starts to tip. “Come for me, come for me and next time I’ll give you something better than my fingers.”

Keith cries out at the feeling, at the sordid promise, and then his body is shaking and coming apart. He squirms at the pleasure, feeling his pussy clench. There’s a flood between his legs, an absolute mess. Shiro slows with his ministrations, letting Keith down soft through the aftershocks.

“Good,” Shiro says, kissing his forehead. “So good.”

##

That night, just as Keith is drifting off to sleep, he’s awoke by a hand slipping under his blankets to grope between his legs. He startles to attention, but then relaxes as he recognizes Shiro climbing onto the bed and on top of him. There’s a brief kiss to his cheek, and then Shiro’s mouth is sliding down to Keith’s throat.

“Was lying in bed and couldn’t stop thinking about you,” Shiro says. There’s a sucking kiss then to his neck that makes Keith cry out. “And since Dad’s at the station all night… you can be loud again.”

Keith remembers then Shiro saying just that morning, _I’ll give you something better than my fingers_. It excites and scares Keith, the idea of more. It’s all so fast and so intense. He trusts his brother, trusts him with everything, it’s just…

His thoughts are cut off by Shiro’s hands on the hem of his shirt, pulling it up and off. Keith’s helpless, even when those hands go back and push down his pajama shorts. In under a minute Keith is completely nude for the first time. He’s blushing, aware of his smallness, of the peaking of his nipples in the cool air.

Shiro is above him, eyes a heavy weight as he takes in all of Keith. “You’re so beautiful,” Shiro says. His hand trails up Keith’s side and then a finger brushes his nipple.

Keith makes a sound at the sensation that zings through him.

“Sensitive here?”

Shiro touches again and gets the same reaction. It’s similar as to when Keith’s nearing his orgasm, a pleasure so sharp he can’t keep it in.

“Hm, and what about…”

Then before Keith can even register it, Shiro bends and takes a nipple into his mouth. Keith cries out loud, and his hands come up to claw at Shiro’s shoulder. It doesn’t stop the man, if anything he grows bolder. He tweaks the other nipple as he sucks hard.

Keith doesn’t come, but there’s a dazzle in his head and a hard pulse between his legs. A gush of slick dampens the sheets.

“Sh— _ah_ —“

“You sound so good,” Shiro says. His hand keeps pinching at the other nipple, and there’s a quake in Keith, something deep and animalistic. He wants it to stop and to go on. Wants Shiro to keep sucking and tweaking the little buds until something… something… happens.

“But I wonder if you’ll sound as good if I suck your clit too.”

Keith gasps, as Shiro shifts down.

“Wait—!” Keith swallows hard, heart battering. Shiro doesn’t stop moving, pushing Keith’s thighs apart to make space for himself. “W-wait!”

Those big hands come to wrap around Keith’s thighs and draw him in. In the dim lighting Keith can see Shiro’s eyes flicker up to him. They’re all black and hungry.

“What baby, isn’t this what you want? I can practically smell your cunt, I know you’re hot for it.”

The words make Keith’s cunt clench. How fast Shiro shifts into this sometimes gives Keith whiplash. He loves it, loves Shiro’s focus and attention on it, but it also makes something anxious and fluttery in his belly. It’s the duality of Shiro that keeps Keith so hooked, the gentle care and this hungry, darker thing.

Shiro bows his head then and Keith is awash in heat. His hands come up to cover his face at the first touch, and every other thought disintegrates.

It’s… hot. _Wet_. Like nothing else. Shiro’s mouth closes over that most sensitive place and he _sucks_. Keith shrieks at the feeling. It’s so much and his legs try to come up and snap together at how sensitive it is, but Shiro’s hands are there. He pins Keith down and then just _takes him_.

The softness is what really starts to pull Keith apart. There was a structured build when he was rubbing on Shiro, it had been rougher against his clit, but the ascent had been measured in some way. Keith had felt like he’d had control.

This is not that. Shiro’s mouth between his legs makes him feel wild. It’s a soft lure that has pleasure spiraling through Keith with every flick of Shiro’s tongue. Every motion feels like it could end him, like Keith’s orgasm could just sneak right in without his say. The heat is burning, the hands keeping him in place are branding. Keith whines and shouts, arching as he feels his whole body wax and wane under Shiro’s attention.

It feels so, so good. Better than anything else has ever been.

And Shiro’s doesn’t stop. The sound is so audible how he licks and sucks, unyielding as Keith rolls his head against the sheets, gasping and pleading and—

Then he sucks hard, and Keith shouts, all the air punched out of him as his orgasm springs up. It’s sudden, and he comes, wave after gorgeous wave of it. The pleasure is thick and syrupy in a way it hasn’t been before, in a way Keith could get addicted to. It’s soft and long, the pulses taking their time moving through him. Shiro keeps his mouth there, lapping more slowly as the pleasure winds down. Keith’s hips are moving against his mouth, automatically eking out the last of the pleasure.

When he begins to come down, he sighs happily. He’s not wiped clear out of his head in the same ways as he has been before. Instead he feels… relaxed.

Shiro picks his head up, and when Keith blinks his lazy eyes open Shiro is looking at him smug.

“Good?”

Keith hums.

Shiro sits up on his knees then, and moves to straddle Keith’s chest. His cock is hard, and it looks massive from this angle. There’s a string of wetness sliding down the head. Shiro takes his hand to it, giving it a leisurely stroke.

“Oral’s really good, feels a lot better than hands.”

Keith can’t help watching as Shiro strokes himself slowly. The rosy head peaks in and out of the foreskin. Keith licks his lips.

“Definitely one of my favorites…” Shiro says. Keith’s eyes flicker up then, and Shiro’s eyes are on his face. It occurs to him suddenly that he should offer.

“How do I…?”

A hand touches the side of Keith’s face gently. “You want to try? You want to make me feel good too?”

Keith’s exhausted, eyes heavy from the orgasm he’s just had, but he feels suddenly like he needs to. He doesn’t want this to be one-sided, doesn’t want to just be the needy little brother.

“Yeah, of course.”

Shiro smiles then. “Good boy. Good. But don’t worry, I won’t make you move for this. You look so comfy there anyway, huh?”

“O-okay.”

Shiro shuffles closer on his knees, then he reaches over for a pillow.

“Head up.” Keith does, and then another pillow is stacked there so Keith is angled a little higher. “There. Perfect. Now just relax, open your mouth.”

Keith swallows, eyes wide, and does so. He tries to quell the spike of fear as Shiro moves closer. He reminds himself that it’ll be okay, that Shiro would never let anything bad happen to him.

As if hearing his thoughts, Shiro’s hand slides through his hair affectionately. “Don’t worry, this is easy.” The petting is nice, and does help. Keith takes a big breath, and then lets it out slow. Shiro’s shifts and then his cock is at Keith’s lips.

“That’s it… you look so good, _fuck_.”

Then he moves his hips, and the cockhead slides over the pillow of Keith’s lower lip and into his mouth. The first thing Keith notices is the salty taste, then the warmth. The natural reaction is to pull back, but Keith tries to fight it. He doesn’t want to disappoint Shiro, doesn’t want to not be able to do something Shiro had done for him. 

“Just a little, just let me in— _ah_ —“ He pushes in more and across Keith’s tongue. Keith can’t help how his tongue moves at that, inquiring at the object in his mouth. “See, nice and easy. Now close your lips around me, but don’t forget your teeth okay, you want to keep them out of the way.”

The instructions are a lot to keep track of. Keith shuts his eyes and tries to focus. He flattens his tongue to cover his teeth the best he can, then closes his lips around Shiro’s cock. It’s strange to have the weight in his mouth, the salty taste of his precome and skin. But also kind of worth it for the sound Shiro makes then.

“Yeah, yeah. _Fuck_ look at you. That’s about all you can take right now, but fuck— we can work on that. Feels so good baby. So good. Now I’m just going to move a little, going to rub just like before. You don’t have to do anything okay, just watch those teeth.”

Keith tries to answer, but can’t. Shiro seems to understand it anyway. He pulls back, cockhead pulling all the way out, and then pushes back in. The sound he makes Keith wants to remember it forever. It makes Keith want to be better than this virginal, inexperienced thing.

Shiro does it again, thrusting slow and shallow into Keith’s mouth, letting Keith get used to it.

“Knew your mouth would feel good. _Fuck_. Could get addicted to this,” Shiro says as he begins to thrust faster. Keith tries to swallow at the building saliva, but can’t manage it so it begins to drip messily from his mouth. “Yeah, yeah, just take it. Almost there baby, you get me so fucking hot. _Shit_.” The soft hand in Keith’s hair suddenly curls to be a fist. The thrusting gets faster, and Keith’s hands come up at once to Shiro’s hips. There’s a spike of sudden fear.

“Just— a little more— can you do that for me? Feels so good Keith— just—“

So Keith doesn’t push away. He tries to breathe, tries to quell the thumping of his heart, the sudden too-muchness. Surely he can do this after all Shiro’s done for him. He wants to be good for his brother, wants him to come and feel as good as Keith did.

The last few thrusts are difficult. They’re too deep, the cock pushing more into Keith’s mouth by Shiro’s eagerness, and Keith’s held in place by Shiro’s hand in his hair. Keith makes a sound of distress, but Shiro only moans and keeps fucking in.

“Almos— that’s it— _take it, take my cock—“_

There are tears in Keith’s eyes, but just as it moves toward too much for Keith to bare, Shiro is bending over him, pulling tight on Keith’s hair. He grunts and Shiro’s cock pulses against his tongue, and then suddenly Keith’s mouth is filling with a hot, salty liquid. He tries to pull away again, but Shiro holds him, fucking Keith’s mouth indulgently through his orgasm. The sounds he makes are so much more than any time before, and Keith clings to those. It drips down his chin and he just tries to get through.

And then it’s over. The cock in his mouth stops spilling, and the hand gentles once more. Shiro pulls back, removing his cock from Keith’s mouth.

Immediately Keith swallows the bitter spill, breathing hard. He feels worn through, and his lips are numb. When he opens his teary eyes Shiro is above him.

“Keith,” Shiro says tenderly. He shuffles to lie down beside Keith and pulls him in, curling him in a tight hug. “Keith that was amazing,” Shiro says.

Keith blinks at him. “Was it?”

A bit of hair is tucked behind his ear. “The most amazing. You’re incredible.”

The words wipe away the pains of Keith’s body. He’s no stranger to hard work, or to doing challenging tasks for the approval of his older brother. He’s all at once proud of himself for sticking in there.

“And it seemed hard for you at the end there, but you can get better, I know it.”

Shiro’s smile at him is so warm and wonderful then that Keith finds himself smiling in return.

“My wonderful, amazing Keith.” Shiro pulls him all the way in for a hug, and it smooths down the last of Keith’s uncertain prickles.

##

The nagging sensation remains. In fact, with every passing day it seems to grow larger, consuming more and more of Keith’s attention. What started as just morning trysts becomes morning and night. It becomes midday. It becomes anytime that their father is asleep or away.

Shiro has him practice blowjobs most of the time. It’s an area Shiro encourages him to improve upon, and Keith, abashedly, agrees. Since Keith’s near useless after an orgasm, Shiro decides it’s best if they focus with their limited windows of time.

It involves a lot of Shiro lying back in bed, dictating how Keith can best go down on him. It’s part instructive, part fun. Shiro is kind, effusive with praise, and Keith melts to hear it. He licks and sucks and does his best to stretch his mouth around Shiro a little more every time. That part is hard with how big Shiro is, but it’s also worth it for Shiro’s reactions. 

Because the reactions are something else. When Shiro finishes he showers Keith in sweetness, and it’s an immediate balm against the bitterness on his tongue. It helps Keith to swallow just how Shiro likes, and then he takes advantage of such sweetness to push himself up and into Shiro’s welcoming arms. When Shiro recovers enough, those large hands move down and touch the pulsing heat between Keith’s own legs. Keith will come, warm and held tight in Shiro’s arms, and it’s near perfect.

But as perfect as it is, day by day the sensation grows. Eventually twice a day is not enough to curve Keith’s growing hunger. Keith’s underwear is constantly wet from his own arousal, and he near squirms trying to stay still and focus on anything. There’s emptiness in him, an itch that he can’t scratch.

It culminates further four days later when their dad is called in for a last minute shift. Keith has spent the morning pacing his bedroom, hot under the collar with no way to relieve it. He’s tried touching himself the way Shiro does, has spent time both in his own bed and the shower rubbing his swollen clit, but it’s not the same. The orgasms are mediocre at best, and that’s when he manages one at all.

So when their dad shouts down the hall that he’s leaving for a shift, Keith’s whole attention shifts. He goes to his bedroom window and watches their father go out to the truck, get in, and start it up.

Anticipation shoots through him, and the truck is barely out of the driveway before Keith’s turned to hurry to Shiro’s room.

His brother is typing at his computer when Keith bursts in. There’s no reaction, it’s not that uncommon for Keith to just stroll in, but not being noticed immediately irks Keith in that moment. Huffing, he marches over and promptly seats himself in Shiro’s lap.

“Oh, hey—“

Before Shiro can even get the words out, Keith’s hands are at his pants, unbuttoning them.

“ _Oh_. Hello then,” Shiro says with that warm, deep tone he has in just these situations. Then there are hands under Keith’s ass, and he’s being lifted up and seated on the desk. It pushes the keyboard and some of the papers off, but Keith doesn’t pay any attention to that.

“Couldn’t wait for Dad to be gone two minutes, huh?” Shiro reaches for the hem of Keith’s shirt. “Naughty thing.” He tweaks one of Keith’s nipples.

“ _Ah_!”

“What’s next? Gonna slip down under my desk and suck me off while Dad’s in the next room?” Shiro asks, unbuttoning Keith’s shorts. “Bet you would. So hungry for cock. Mmm.”

When the underwear comes off, Keith can feel how wet he is. Shiro’s hands come back to his thighs and push them apart obscenely.

“Look at you,” For once Shiro’s hand slips down past Keith’s clit, and touches the slick. Keith groans, clenching at how that emptiness swells inside him. “Yeah. Yeah I think we’ve waited long enough. You need it bad don’t you?” The finger swirls around Keith’s hole, teasing. “Need something here, don’t you?”

Keith whines. Heat spikes in his core and it’s strange, somehow different from the times before. Right behind it though is the fear. He’s never…

But then he hasn’t done any of this before Shiro. Even so, the prospect is sort of scary.

Before Keith can get any words out though, a finger is pushing into him. Shiro’s finger.

The sensation rolls through him, knocking the thoughts clean out of his head.

“Holy shit,” Shiro says, but Keith can’t focus on anything but how his cunt is clenching around that digit.

“It’s like you’re sucking me in. That’s so hot— I want— Keith baby, you’re gonna let me fuck you, aren’t you?”

The finger slides back out, and Keith manages a breath, a moment of clarity. “I— I don’t— it feels—“

“Yeah,” Shiro says and plunges his finger back inside. Keith’s whole body arches with pleasure. “Yeah, looks like it feels good. Gonna feel so good on my cock, you’re,” He pulls his finger out to press back in just to feel Keith pulse around him again. “Fuck. Okay.”

Then the finger is out of him again, and Shiro is undoing his pants properly and pushing them down. By the time Keith’s recovered a little of his sense Shiro is back in his space, cockhead just at Keith’s dripping hole.

“Shiro!”

“It’s okay. Gonna take care of you.”

Keith opens his mouth to say… something, but instead Shiro shifts forward and pushes _in_.

It’s different from the finger, hotter and thicker, and so, so much. Shiro’s cock slides all too easily in with how wet Keith is, and Keith can’t help the needy-overwhelmed sounds he makes. His head falls back hitting the monitor or the wall, and it’s all he can do just to curl his hands into Shiro’s shoulders as his cock forcefully fills up that empty space inside Keith.

His cunt flutters madly, and it feels _good_. Better when Shiro grunts and bottoms out.

Shiro bends his head into Keith’s neck and swears. “Baby your cunt is… _stars_ , it’s like it’s milking me. Ugh. Should have been doing this weeks ago.”

Keith makes a low, strange sound. His mind is fuzzy and strange, and it’s hard to think. All he can feel is the waves of pleasuring lapping at all his edges. He wants Shiro to move, wants—

He shifts his hips trying to get a little friction and Shiro moans.

“Tight.” A hand pets down Keith’s side and then back up. It wanders in and a thumb rubs over one of Keith’s nipples.

And that—

It’s like a lightning strike. Keith’s whole body jerks, and then suddenly, inexplicably, he’s coming. He moans, clutching at Shiro as his cunt pulses. Shiro swears and stays in him, stays deep, and it’s good. So good. _Perfect_. Keith moans through the orgasm, head rolling against the wall.

“Did you just…?” Shiro sounds incredulous.

Keith can’t speak. There’s another pinch at his nipple and he mewls.

“ _Fuck_ ,” Shiro hisses. There’s a tug on his other nipple, then both at the same time. Keith screams, a hot white edge of pleasure striking through him.

And instead of leaving him satisfied, it makes that itchy unsatisfied thing move closer. He arches, pressing his nipples into Shiro’s hands.

“…More,” Keith says, breathy and lost.

Shiro does. He tweaks and pulls at Keith’s nipples, and every time is a shock, growing more intense. Shiro’s hips start to move, pulling out to push back in with a slick sound. It feels good, right. He needs _more_.

“Yeah… Ke— fuck you look—“

“ _P-please_ ,” Keith’s head rolls back against the wall. He can’t do anything but try to hold the position, ride out the barreling pleasure.

Shiro curses again, starting to move faster. He pinches harder and Keith wails. The thing is so close now, and he needs it, _needs it._

“It’s never felt— baby every time your cunt squeezes me I feel like I’m gonna blow. Fuck, how do you feel this good?”

Keith winds higher and higher as Shiro abuses his nipples. They grow sore beneath his fingers, but it only makes it better. There’s a pressure in Keith’s chest, in his whole body, and he needs to let it out. He needs release.

Shiro fucks him without pause, railing deep into his pussy. Keith’s hands claw into the back of Shiro’s neck and he cries, screams, whole body tightening and—

And then it’s there. _Here_. Something like a sob chokes out of Keith’s throat, and the pleasure subsumes him. It’s nothing like any of the other orgasms, it has a width and breadth he can’t contain. It’s a release everywhere. He feels his cunt clench and pulse, a flood of wetness.

“You’re—“ is all Shiro says, and then he’s crushing Keith, cock shoved deep and twitching. There’s heat and release and waves and waves of pleasure.

Keith doesn’t try to do anything but breathe through it.

There’s a long time then where nothing happens. They’re plastered together, sticky and relearning how to breathe. Keith feels his whole body reassembles itself slowly.

When Shiro does pull back, the cold air is nice. His chest is burning along with between his legs. Shiro’s no longer inside him, and he doesn’t remember when that happened.

“ _Keith_ ,” Shiro says, voice full of wonder.

It’s a while longer still until Keith can open his eyes. He’s exhausted finally. Whatever that thing is that’s been dogging him has finally gone away. He feels… drunk. He’s never been drunk, but he imagines it’s what it must feel like. Floaty and nice.

“Hm?”

“You’re…” Shiro’s still in his space, and his hand is just on Keith’s chest. Keith tilts his head down to look.

It’s wet.

Shiro’s fingers move in again to tweak the swollen bud. Keith jolts at the feeling, but then watches more wetness leak from the tip.

“Baby. You…” Shiro pinches the other and finds the same result. “That’s so hot. Wet even here, huh?”

Keith flushes. The way Shiro’s speaking about it makes it seem as if it’s unusual. Keith frowns.

“Is that… okay?”

Shiro bends down and drops a kiss onto his pouting lips.

“ _Very good_. You’re so special Keith. Your body is amazing. Never felt anything so good around my cock, your cunt practically milked me, felt like a mouth.” He smiles then, something with an edge of wickedness. “And now I can return the favor. I can milk you baby. Felt good, didn’t it?”

Keith swallows hard. The way Shiro is looking at him just does things to him.

“Yeah. Felt… like relief.”

“Yeah,” A hand moves up and cards through Keith’s hair sweetly. “Looked like you finally got some relief. We’ll just have to make sure to take care of you in the future.”

Keith tilts his head into Shiro’s hand. Already his eyes are drooping though, he’s exhausted.

“Alright, but first thing first. Let’s get you cleaned up and into bed, hm?”

Keith makes a small noise as Shiro moves and scoops him up. There’s the sensation of wetness dripping out of Keith, of Shiro’s come sliding down his thighs, but he curls his head into Shiro’s throat and ignores it. Shiro will take care of him.

##

Less than a day later, the feeling returns. Keith can recognize it then, can feel the weight of it in his chest and between his legs. He squirms in bed listening to their father move around the living room.

He picks up his phone and opens a text to his brother. Before sending though, he has a better idea. A bold and sort of scary idea. The heat in Keith’s body drives him on.

He pulls up his shirt and takes a hand to his own nipple. It’s still a little sore, but this time it takes nearly nothing to get the wetness to appear.

Quickly he snaps a photo, and before he can feel embarrassed by just how lewd it looks, nipple peaked and dripping, he sends it.

Less than two minutes later there’s a knock at the door and then Shiro comes in.

Keith looks at him wide-eyed. Shiro mimes putting a hand to his lips in the signal of silence. Then Shiro is crawling into his bed.

“What are you doing?” Keith whispers.

Shiro stays under the comforter, but lays himself across Keith’s legs. His hands begin pushing up Keith’s sleep shirt.

“You think you can send me something like that and I wouldn’t come?” Shiro gets the shirt up over Keith’s nipples. “Been thinking of nothing but getting my mouth on these.”

“Dad’s right in the next room!” Keith hisses quietly.

Already Shiro’s hands are pinching, and Keith’s forced to slap a hand over his own mouth.

“Well then I guess you’ll have to be quiet,” Shiro grins wickedly.

“Shiro!” The protest is weak and losing traction as Shiro continues to play with him.

At a hard pinch that has wetness dribbling down Keith’s chest, Shiro’s eyes flicker up to meet his. Keith’s bitten down on his palm to quiet himself. “Want me to stop?”

Keith’s heart is pounding in the fear and arousal. Their dad could come in at any moment. He tends to knock before opening the door, but that’s little time for them to make this look like something proper.

Shiro continues toying with him, fingers teasing the sore tips, and Keith can’t manage to think. He’s sliding down toward some gauzy place, and he knows Shiro knows it.

“Don’t you want to know how it feels when I suck your tits dry baby brother?”

He doesn’t give Keith time to answer. He lowers his mouth to Keith’s dripping nipple and latches on.

Keith shrieks and drags his comforter up to press against his mouth. It’s a hot, delicious sensation as Shiro begins to suckle at him.

Wetness starts between Keith’s legs, and he squirms as his body revs up. There’s no slow build this time, no pause. Shiro keeps his mouth on Keith, other hand reaching over to tweak Keith’s other bud. He sucks and Keith can feel the liquid pulled out. It feels strange and amazing, and his clit _throbs_ for stimulation.

Shiro’s completely under the covers, and it feels so much more dirty than anything else they’ve done. If their father walked in right now there would be only the thinnest layer of deniability. Shiro’s a large lump under the blanket, and the sound of him sucking at Keith’s tit is—

Keith’s hips arch against Shiro in request. It’s only then that he pulls back.

“Want my cock again? Yeah, yeah you do,” a hand slides down Keith’s body and into his underwear. Fingers touch around Keith’s hole. “You’re drenched just from that. _Fuck_.”

Then Shiro is shuffling up, pulling the blanket up over him and Keith. He’s suddenly above Keith, looking down at him with a dark hunger.

“Gonna be quiet for me,” Shiro says. His hands tug down Keith’s underwear, and then he spreads Keith’s thighs. “Gonna take my cock, let me feel that sweet little pussy clenching around me.”

And then his cock is at Keith’s entrance, before Keith can remind him that their father is just a thin wall away. Keith’s too wet and the slide is easy. Shiro groans hot and low, not taking it slow but pressing his thick cock all the way in, filling Keith.

It’s just as big the first time, but this time Keith’s already fuzzy, already twisted up in the fear of getting caught and the pleasure of Shiro sucking at him. Shiro takes that advantage and begins to moves atop him, sliding deep, helping himself to Keith’s body Keith mewls and a hand presses over his mouth.

“Shh, just let me,” Shiro pants. “Wanna feel your cunt when I suck you.”

He arches himself then and gets his mouth on Keith’s other tit.

It’s better, so much better with Shiro filling him up. His hole clenches around Shiro’s cock, and it’s _amazing_. The shocks dazzle through him as Shiro nurses at his teat.

It’s a steep build then, just like last time. Keith whines, muffled against Shiro’s hand as Shiro rocks into him. The sounds are obscene, slick and messy as Keith drenches Shiro’s cock. Shiro slurps and sucks, switching only when the pressure begins to wane and the milk from his tit begins to slow.

The heat beneath the covers builds, and before Keith even realizes it, his body is rigid and moving with Shiro. His body is helping Shiro to stay deep, rocking against all those spots that Keith’s needed to have touched for so long. Everything is slick and overheating and so, so much.

Keith is lost completely to it. His body isn’t his own anymore, but Shiro’s. Shiro’s to fuck and suck as he pleases. And he knows it feels good for Shiro, he knows from the sounds his brother is making, the heavy fuck of his cock in Keith’s hole, that it’s _good_.

If his mouth weren’t so occupied, Keith knows it would be spewing the most filthy words. The memories swirl around Keith and pull him under. He likes being good for his brother. He likes giving his brother something no one else can, that he’s different and that means that Shiro can’t get this anywhere else. That maybe Shiro is just as addicted to this as Keith is—

Keith comes hard, sudden and overwhelmed. It’s a gush of feeling through his whole body, and he lets it take him over. He’s just aware of Shiro’s burying himself in Keith’s throat and swearing, rutting hard into Keith.

“Fuck, fuck, clench on me, just— _ah_ — gonna cream your pussy—“

Shiro grunts then and there’s twitching, a series of pulses that encourages Keith’s own. Shiro comes deep inside him, working his cock through the tight, wetness of Keith. He fucks Keith full.

Keith can barely breathe, barely think. His mind’s gone, flattened by the orgasm and the pulses that keep running through him. He’s floaty, absolutely ruined. When Shiro does push up off him and move the blankets down, Keith can barely open his eyes.

“Baby?” A hand comes to his cheek and Keith looks dazed up at Shiro. “Feeling good?” There’s a low laugh, and then some movement of the blankets. Keith’s too walloped to care as Shiro bares him to the room, sliding back down his body to between Keith’s legs.

“You look so good like this,” Shiro says. He takes his hands to Keith’s pussy lips and spreads him. “You even squirted that time. Look at this mess. So fucking hot.” His hands touch Keith’s sore hole. “My come dripping out of you,” a finger swipes some up and then pushes it back in Keith’s hole. “I have to…”

Shiro reaches over then and grabs his phone that’s fallen off the bed. Keith blinks blearily down at him as he takes the phone to between Keith’s legs.

“Wanna have a little something later, wanna remember just how you looked, fucked full and dick-drunk.”

Keith hears the click of several photos, then Shiro touches him again, pulling open his messy hole to take a few more. Slowly Keith becomes aware of just what they’re doing. He becomes aware that he’s spread out and naked on the bed. If anyone were to come in, they would be able to see immediately his swollen red pussy, dripping come.

He tries to close his legs only to be met with Shiro’s hands.

“Don’t be shy now. I’m almost done. Just want to get a good look at my work. It’s not every day I get a cock-whore so ready to squirt on my dick.”

There’s a few more pictures, and then Shiro does move back up. Keith sees come on his brothers fingers. Shiro takes those messy fingers to Keith’s tits and squeezes one reddened nipple.

The sensation is muted now, but Keith watches a tiny bead of milk rise to the tip. Shiro snaps another photo with his clean hand. The finger swipes of the milky bead and then there’s that look again on his face, the one from before that Keith never did figure out the reason for.

This time Shiro turns his hand and offers it to Keith’s mouth. “Open up.”

Keith does so without thinking, mindlessly obedient. Shiro presses his fingers in and the taste is salty, musky. He realizes then that he’s tasting not only Shiro’s come, but his own cunt.

“Perfect,” Shiro says as Keith licks and sucks his fingers clean. “But now I guess we should clean you up. There will be more opportunities when Dad’s not in the next room, huh?”

Keith blinks at him, still unable to do much with his body, he’s so, so tired. Shiro’s fingers slip out of his mouth and smear saliva across his cheek. He feels utterly debauched.

In the end though that’s okay, because Shiro scoops him up and takes him to the bath. For the first time he doesn’t leave Keith to fend for himself, but takes to the washing himself. The tending that follow makes Keith melt further, until Shiro’s fondly lifting him out of the water and towel drying him off. He’s placed then gently back into his bed and given a sweet kiss. 

##

It goes on like that. Nearly every morning Keith wakes with that urgent need. He and Shiro either fuck loudly because their dad is gone, or sneak around the house and then out into the desert. Keith feels near insatiable, but every time he brings it up Shiro only kisses him quiet and says it’s a perfectly normal part of puberty.

At one juncture Keith tries to google it, but doesn’t come back with many results that are similar to him. _Different like your mother_. Neither his dad or Shiro ever go into what that means, and Keith isn’t even sure he should ask.

And personally it’s just hard to focus on even those kind of questions these days. The more Shiro fucks him, the more Keith needs it. His nipples begin to drip all the time instead of just when Shiro is sucking on them. More than once Keith pulls Shiro outside the house just to have him suck his tits until they stop seeping wetness in his shirt.

Most of the time that ends with Keith bouncing on Shiro’s cock, and Keith doesn’t mind. Like Shiro says, it’s only fair that Shiro also get something out of it.

He doesn’t even mind the occasions when he wakes with Shiro already balls-deep inside him. Shiro is doing so much to help Keith, to make his body settle, so surely he can offer his pussy up whenever Shiro needs it.

Even if Shiro needs it a lot. Instead of masturbate, Shiro turns to just using Keith’s pussy. Keith knows this because Shiro tells him, praises him for feeling so much better than Shiro’s hand. Those times are quick encounters, Shiro rutting hard and deep until he groans and comes inside Keith. Then they go about their day afterward until Keith’s tits are too heavy to ignore, or his pussy begins to ache for more. Then Shiro will secret him away and spend half an hour sucking his swollen tits until he’s empty again.

Summer goes fast like that. Keith thinks about Shiro’s cock almost constantly, and almost nothing else. He’s always dripping come from Shiro’s last load, and his brain is buzzy, his nipples swollen.

He’s Shiro’s little cock-toy, through and through, and he finds that he doesn’t even mind. 

Thoughts of the Garrison, of any other future slip away from Keith. Slowly he even begins to forget about being careful, about hiding it from their dad.

Shiro catches him on one such occasion almost falling to his knees in the living room while they’re all watching TV. Shiro plays it off like a fainting spell, excusing them and promising to take care of Keith. They spend the next hour in Keith’s bed with Shiro’s cock shoved down Keith’s throat half in punishment for almost getting them caught. When Shiro does eventually spill, he pulls Keith up and sucks his teats dry as Keith comes twice in succession before settling.

“Dad said your puberty should settle down in a little while,” Shiro says a week later, caressing Keith’s thighs as he bounces on Shiro’s cock. “I told him you’d been struggling to focus, and we agreed to put off the Garrison for a little while. In the fall instead I’ll get us an apartment off base.”

Keith’s barely listening, his mind awash in pleasure as Shiro tweaks his nipples and smears the wetness around.

“That way I can take care of you properly,” Shiro says. “Just imagine it, I could have you seated on my cock all day. Could fill you up with load after load, plug you full.” He plays with Keith’s tits a little more, cupping them. “And these are getting bigger. Heavier with milk. I’d love to see how big they’ll get. Could get you a proper milking machine. Just leave you strapped up and hole ready for whenever I need. Perfect little fuck toy.”

Keith wails as Shiro nails him deep. It sounds good, everything that Shiro says sounds good. He makes a sound of assent.

“Good,” Shiro says, voice dark. “Soon I’ll have you all to myself, and then we can see what else your body can do.”

Keith mewls, happy to have his brother taking such good care of him. He knew Shiro would.

**Author's Note:**

> All thanks to @pissangel for requesting this fic, I've been dying to write some brothers fun for a while. I hope you enjoyed!!


End file.
